The RepositoryManager pre_process_request
does guard against the secondary requests (the if handler is not Chrome(self.env):
test does that).
The timeline pre_process_request
does nothing and its post_process_request
does also a check (the if data:
test).
So in both cases, there's no real performance impact.
But for the next release, I'd like to change the way the repository synchronization is done (as that's not scalable with the MultipleRepositorySupport) and that IRequestFilter filter will be history.
Setting milestone to 0.12 as a reminder to clean-up the IRequestFilter.